Technical Field
The present invention relates to the field of macromolecular materials, in particular to a hybrid organic silicon thermoplastic elastomer and a preparation method thereof.
Description of Related Art
By virtue of their unique chemical structures, organic silicon elastomer materials have excellent properties, and can be widely applied in buildings, automobiles, new energy, roads, bridges, electronics, space flight and aviation, and medical industrials. Traditional organic silicon elastomer materials usually achieve corresponding properties by adding reinforcing inserts such as calcium carbonate and silicon oxide and additives such as cross-linking agents, coupling agents and catalysts in organic silicon polymer base stock during the mixing process. The organic silicon polymer base stock and the cross-linking agent form a stable chemical cross-linking structure at room temperature or at a high temperature, so materials have certain physical properties. However, it is very difficult to damage stable chemical bonds once the bonds are formed, so the organic silicon elastomer materials can be processed once only and do not have elastic heating processing and multiple repeated processing properties like plastic and thermoplastic elastomers.
Blends of organic silicon and other macromolecular materials can be prepared by blending macromolecules, but the organic silicon materials have low surface energy and an obvious separation phenomenon exists after organic silicon materials and other macromolecular materials are blended, so the final products lose use value. Chain segments of the organic silicon polymers can be modified by using the macromolecular synthesis method or chemical modification method, and through importing new molecular chain units, a hybrid organic silicon elastomer material can be prepared. Such novel structure allows co-existence of the organic silicon chain segments and other macromolecular chain segments in the molecular scale, so the material has the features of the organic silicon materials, and is endowed with better properties, for example the enhancement of physical properties, improvement against corrosion resistance, and increase in adhesion.
At present, various organic silicon hybrid materials such as organic silicon-polystyrene copolymer, organic silicon-polyethylene copolymer, organic silicon-poly(urea)urethane copolymer, and organic silicon-polyamide copolymer can be prepared by using the macromolecular synthesis method. Due to the raw materials and difficulties in the process, organic silicon-poly(urea)urethane materials prepared by using the condensation-polymerization method have the biggest industrial production prospect. In particular, the organic silicon-polyurea copolymer has rigid urea bonds, so the organic silicon-polyurea materials have drawn much attention in virtue of its excellent physical properties and thermoplastic processing properties. Patent EP 0250248 discloses a method for synthesizing a linear organic silicon-polyurea segmented copolymer by using a chain extender. Patent US 20040210024 A1 discloses a method for preparing an amino-terminated silicone oil and linear organic silicon-polyurea segmented copolymer.
At present, the linear organic silicon-polyurea segments are mainly linear copolymers. When used as the thermoplastic elastomer material, the rigid polyurea structure forms physical cross-linking points by the effect of hydrogen bonds between molecules. Linear copolymers have high viscosity and poor mobility during processing and are required to be processed at a relatively high softening temperature. In comparison with the linear macromolecular chains, branched macromolecular chain polymers can effectively enhance the processing mobility of the organic silicon polymers and improve the processing performance of the organic silicon polymers. At present, there has been no report on an organic silicon-polyurea hybrid thermoplastic elastomer with high processing mobility seen yet.